I have finished six or seven 100 mile races. I've observed that the only apparent constant among all finishers is above average fitness, a reasonable approach

I have finished six or seven 100 mile races. I've observed that the only apparent constant among all finishers is above average fitness, a reasonable approach to food and drink while racing, and a total commitment to finishing. Every race has some bare foot runners and some Hoka devotees. You see fat people and thin people. Old and young. Every finisher suffered tremendously, yet he or she refused to quit.